atomic weight

noun

Definition of atomic weight

: the mass of one atom of an element specifically : the average mass of an atom of an element as it occurs in nature that is expressed in atomic mass units — see Chemical Elements Table

Examples of atomic weight in a Sentence

Recent Examples on the Web Plain ol’ carbon — carbon that has 6 protons and 6 neutrons for an atomic weight of 12 — is far more stable than radiocarbon, and therefore vastly more plentiful in Earth’s atmosphere. Rebecca Coffey, Forbes, 3 Mar. 2021 Kaiser and his colleagues chose rhenium because each atom is relatively large, compared more familiar atoms like carbon and oxygen that are less than one tenth of its atomic weight. Theresa Machemer, Smithsonian Magazine, 22 Jan. 2020 This approach succeeds most of the time, when the issue is, say, the atomic weight of hydrogen. Adrian Bardon, Scientific American, 26 June 2020 The atomic weight of the sun is composed of 92.1 percent hydrogen and 7.8 percent helium, with traces of carbon and nitrogen. Jennifer Leman, Popular Mechanics, 3 Nov. 2019 How to Read the Table Many periodic tables include the atomic number (number of protons) and atomic weight (which depends on protons and neutrons). Bill Andrews, Discover Magazine, 26 June 2019 So Bormanis came up with his own fictional heavy element, dysonium (named in honor of physicist Freeman Dyson), something with an atomic weight in the 130-135 range—well above the transuranic elements in the period table. Jennifer Ouellette, Ars Technica, 29 Dec. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'atomic weight.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of atomic weight

1819, in the meaning defined above

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The first known use of atomic weight was in 1819

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Dictionary Entries Near atomic weight

atomic volume

atomic weight

atomise

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Cite this Entry

“Atomic weight.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/atomic%20weight. Accessed 27 Nov. 2021.

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More Definitions for atomic weight

atomic weight

noun

Medical Definition of atomic weight

: the mass of one atom of an element specifically : the average mass of an atom of an element as it occurs in nature that is expressed in atomic mass units — see Chemical Elements Table

More from Merriam-Webster on atomic weight

Britannica.com: Encyclopedia article about atomic weight

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